What determines the rate of fire of a machine gun, and how can that rate of fire be determined or changed from a design perspective? Let’s talk about pressure, mass, and distance…
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According https://www.armyrecognition.com/news/army-news/2025/israel-acquires-us-xm250-light-machine-gun-chambered-in-7-62x51mm
Recently IDF acquired US XM250 Light Machine Gun Chambered in 7.62x51mm
How it did affected Rate-of-Fire of said design?
There are lots of things that change the rate of fire on a machine gun depending on the mechanical operations
One for example on the roller lock
Bolt gap can change operational speeds The locking angle can either release the system quicker or keep it longer in battery this controls the gas that is used in the system the other thing that can change the rate of fire is the recoil Spring a stronger Recoil Spring will cause the weapon to function at a higher rate of speed with a higher rate of fire, also ammunition plays a big role in these systems Due to the gas pressure a stronger and more powerful ammunition will make the weapons rate of fire increase due to overpressure. Recoiling buffing Can also play a role in the rate of Fire in these Machine guns I Am Only speaking on the roller lock system.
Also I forgot to mention resistance In the feed mechanism can play into Rate of fire.
For example an HK21 if the belt is heavy you will see the rate of fire change when it gets to the end of the belt it will speed up This is cause because of resistance of the heavy belt at the beginning of the cycling rate and as the belt empties the resistance is lightened speeding the weapon back up to its normal rate of fire.
The easiest way to think about this is in terms of energy: How much are you tapping out of the cartridge, and what are you using to run the mechanism?
As well, what are your energy returns coming out of the recoil spring system/buffer?
Work those out, understand them, put them into an equation and you can work out what your theoretical rate of fire ought to be. Once you’ve done that, and validated it by actually working with the mechanism, then you can begin to understand what all goes into the rate of fire and possibly be able to work out how to adjust it.
You’ve got an energy budget to work with: How much can you take out of the cartridge energy before affecting ballistic performance? How much can you put into the recoil assembly, and how efficiently do you get that back?
It is possible to change rate of fire through very simple and entirely counter-intuitive means. M60 machineguns, for example? You can, when the damn things are worn in, use the sear to reduce the rate of fire by riding it juuuuuust enough to get the sear to barely catch the sear notch on the op rod. You want full-rate? Pull the trigger and keep it down.
You can’t do that on other designs, for whatever that’s worth.
It’s all about the energy; lots of energy, low-friction on the recoil/feed/locking systems? You’re producing a high rate of fire. Change any of those, and you’re lower. Or, even higher…
What’s interesting is to observe a change in the rate of fire from a difference in mag spring strength. If you were to take a very old, very worn M16 magazine, put it into an M249 in magazine-fed mode, and you’d get one rate of fire. Do that with a brand-new HK steelie? One with a heavy spring? Different rate of fire, notable enough that you could hear it. The HK mags were usually slower, which I ascertain stemmed from the system having to do more work to get the rounds out.
I don’t think people really appreciate how carefully balanced fully-auto systems are, or what huge effects seemingly minor changes can produce in performance.
“(…)carefully balanced(…)”
If you need that then use https://guns.fandom.com/wiki/Salvator_Dormus_M1893
Did Kirk just say something nice about the M60?
Nope. That little “trick” would have and should have been totally impossible if the designers of the M60 had had the wit and wisdom to copy the spring-loaded secondary sear of the MG42 and MAG58.
I have, however, said very nice things about the barrels of the M60. Not the barrel assemblies, just the barrels… Those were a triumph of mid-century American manufacture, being the only successfully mass-produced Stellite barrel for a 7.62mm-class MG.
Too bad they only came on an utter POS like the M60.
I’d suggest that the ability to affect the rate of fire via piss-poor trigger control isn’t necessarily a good thing, either. As it was, the stated 600rpm rate on the M60 wasn’t what it should have been, in my opinion. But, then… I like to use my MG teams the way that the Germans did.
Kirk:
Good to know the order of the universe has been restored.
I agree about the Stellite liners. Well done to the Americans for getting that done. Did they not share the technology with their allies?
Do the M240s use Stellite barrels?
Unless they changed the Technical Data Package, the M240 still uses the rotary hammer-forged conventional steel barrels.
From what I understand on the issue, the manufacturing techniques necessary to make Stellite barrels are not amenable to the CHF process, and the CHF barrels are “close enough” to the performance of the Stellite ones that nobody really gives a rip.
FN barrels for the M240 were good enough that for awhile there, whenever the blanks came up on the market, the match shooters glommed onto them with a manic glee because they were very long-lived and extremely accurate. The whole question of “Stellite as a barrel material” was an artifact of a certain 1960s-ish manufacturing milieu, from what I understand. The Stellite had to be machined, carefully and expensively, and then used as a shrink-fit liner in the actual barrel. Whoever was doing that in the US, and it may well have been SACO-Maremont, they managed to scale it down from the .50 caliber barrels, and make it consistently and affordably enough that it became a “thing”. FN tried it, Royal Ordnance tried it, and I think Rheinmetall tried it, only to founder on the “costs” issue. There were proprietary techniques and technologies involved. When the CHF barrels came in, the resultant product was “good enough” that they decided Stellite wasn’t really necessary.
One of the areas I kinda wish someone would go into would be all these enabling technologies. You do the reading, you talk to the people who were involved, and you can only get the vague outlines; I’ve never been able to find any real technical references to Stellite barrel production, and most of what I know I have through peripheral or secondary sources, at best. Hell, most of it would be pure hearsay in a court of law…
“(…)references to Stellite barrel production(…)”
As name imply, it was product of Haynes Stellite Company https://usautoindustryworldwartwo.com/haynesstellitecompany.htm therefore I suspect their archives might contain said entity.
Stellite: A History of the Haynes Stellite Company, 1912-1972. By Ralph D. Gray. Kokomo, Ind., Stellite Division, Cabot Corporation, 1974. Pp. 112. $3.50, paper possibly might furnish further details, but I was unable to unveil neither useful preview nor even content summary I am unable to say if it does have desired reference.
Thank you, Daweo… Unfortunately, that reference has virtually nothing in it about barrels. Just valves and valve seats, forever…
I’m pretty sure I got that one out of the library system, way back when, circa the late 1980s. There’s a serious paucity of information on weapons and Stellite, based on that search. Maybe more out there today, but… I kinda doubt it. This is the same system that produced a requirement to re-invent Fogbank, for nuclear weapons production. Which is something you’d think they’d have kept written down somewhere…
Maybe this Stellite has some strategic application in some stuff (rockets, nuclear weapons?) that technical details are still more or less closely guarded secret.
@Storm,
So far as I know, it’s just that it’s a tiny and esoteric part of the Stellite industrial history.
Lots of this stuff simply doesn’t get popularized or even really recorded. I was using the Fogbank thing as an example.
Kirk:
Thank you for your helpful reply.
So it seems the Stellite liner has gone down the memory hole, like a lot of forgotten technology.
It is my belief that the Stellite barrel meant that the M60 team should not have needed to change barrels when using the gun as an LMG. That helps to explain the clunky barrel change, it would have only been needed when the M60 was on a tripod. That further explains the otherwise bizarre decision to attach the gas tube to the barrel. It would have meant a clean gas tube with the new barrel when in support mode.
Perhaps I am overthinking it, but I felt there had to be a reason to attach the gas tube to the barrel, when no-one else had ever felt the need to do so. As you say, these reasons are now lost, I doubt any of the M60 design team are still around to tell us, and any that are left are probably in witness protection.
@JohnK,
I wouldn’t say it’s gone down a memory hole, because I believe they’re still producing them for the M2HB and what few M60 MG systems they’re selling. It’s not so much that they’re “forgotten tech” as it is they are “unnecessary in the face of more affordable CHF barrels”.
I’m sure that the committee of “designers” that produced the M60 thought that the provision of Stellite barrels would do precisely as you say. Unfortunately, they did not work out that you still needed to change the damn barrels in what amounted to the SAW role, off the bipod. The lack of an ability to quickly and easily swap the barrel in that mode, which is enabled by every other damn GPMG design out there, in that they didn’t attach the bipod to the barrel…? Yeah; evidence of utter unfamiliarity with the things an MG team does.
I’m sure it was a selling point to someone. Someone without much in the way of experience as an actual gunner on an actual GPMG. If you were coming over from something like the M1919A6, well… It probably looked reasonable.
And, like you say… All the reasoning and assumptions behind the M60 “feature list” are apparently lost to time. So far as I’ve been able to tell, they basically just threw that design together, and there wasn’t any overarching rationale behind it. Just a rotating committee of “designers” who never really put their name to it. And, from what I’ve been able to tell, they did the majority of the design work without input from actual MG team members, just the sainted “officer class”. The responsibility for the design is so diffuse that I’m pretty sure you wouldn’t be able to tease out any names of the responsible parties, which is a reason that nobody has ever done a “coffee table book” on this system. The documentation just isn’t there…
Or, at least, I’ve been unable to find it. You would think it exists, somewhere in the archives, but… Wherever it is, if it exists, it isn’t accessible. And, I tried… Even one of the archivists at ARL, Army Research Laboratories, couldn’t find anything. Which we both found fairly puzzling, because you’d think that something as important as the M60 would have left some footprints, somewhere. Supposedly, there was a huge mass of documentation from Springfield Arsenal that went up in literal smoke about the time of the Ichord Committee, which was where all of his internal-to-the-system inquiries bottomed out. I’d heard rumors from people who were around at the time that a bunch of stuff was destroyed to “protect the innocent” being called before the committee, and that little tidbit of data sort of argues towards that having actually happened.
Casual acquaintance of mine was a guy who did those “coffee table books”, and when he looked into the M60, he said he’d found the same issue: A lot of the documentation you’d think would be there…? Just isn’t. Truth of that, I cannot tell you; I can tell you that everything I’ve tried to find that stuff has turned up nothing in the way of a paper trail saying why they did what they did. Maybe it’s out there, but… I think that there was some pre-emptive cleaning out of the paper trail, lest the responsible parties get called out on it all. The actual cost of the M60 program during Vietnam was not at all insignificant, per reports of the guys I know who were involved in it all. My warrant officer informant who was a part of it all told me about what amounted to herculean efforts to keep the guns running, which a lot of the users never saw. He remembered doing inspections of guns when they came in out of the field to the basecamps where they’d wind up replacing every single one of the weapons in a company because they were failing gauging and had stretched receivers and loose rivets. Average lifespan on the weapons he described was somewhere well south of 20,000 rounds, which sounds reasonable until you consider that the ammo expenditure rate for some of those units was in the neighborhood of a few hundred thousand rounds a month.
If you want corroboration for all that, look up Stan Goff’s “Bloods”, which is an oral history of the Vietnam War from the perspective of a black enlisted machine gun team member. He describes exactly what happened to me on a range, having the rear trunnion basically fall out of the receiver due to the rivets failing. Only difference? His took place at the end of a major firefight, and mine happened on a peacetime range. Thank God… Only took two or three months before they replaced that gun through the supply system, and that was at the height of the Cold War in Europe.
I’ve nothing positive to say about the M60 as a weapons system.
Awesome video Ian! I am very interested in devices that reduce the rate of fire in a machinegun. I think this would make an excellent video.
Then this https://guns.fandom.com/wiki/McCrudden_light_machine_rifle might be of interest for you.
Look at the rate reducer in the VZ61 Scorpion.
https://www.youtube.com/watch?v=c-Ne1_txtrc
Basically the bolt is held back for the time it takes a weighted rod to be pushed down by the bolt then pushed up by a spring.
Also I ran across rubber recoil buffers for Uzi’s that are different thicknesses. The thicker the buffer, the shorter the bolt travel distance/time, thus increasing the rate of fire.
Yes, the Sa-61 vertical retarder – same idea in Stechkin APS. Also there is a spring-loaded but horizontally-oriented retarder in PM-63. AND going a level up – the hook-up retarder in AKM. AND going two levels up – buttstock retarder hook of FM 24/29 (Chatellerault) LMG many moons earlier on. AND a MAS 1907 blow-forward machine gun with hydraulic buffer governing the rate of fire from 4 to 400 RPM! But these are all mechanical contraptions, while you can change ROF by changing weight of bolt – look up Czechoslovak ZK-383 SMG with an add-on and off weight in the bolt. And there’s an old D-Cell trick in the Swedish K, which falls into the Ian’s ‘shorten the bolt-throw’ category: take a Swedish K, open the back of the receiver, jam a D-Cell into the return spring, close the receiver back cover, load, cock, and enjoy a 550 rpm SMG going at 750 rpm (ball-park figure, never clocked it – but it really goes faster). MG-42/59 / MG1 with a light and heavy bolt also added /reduced some 200 rpm (750 with heavy and 950 light, if I remember well).
The M1918A2 BAR had a rate reducer that (as I understand it) works similarly to the Vz 61’s, with a spring-loaded whatsit in the stock, too. Dropped the ROF from ~550-600RPM down to ~300-350, which seems more practical in a gun like that, but thanks to the placement it often got gummed up and didn’t work. A better version was apparently installed on the FN and foreign variants with pistol grips as well, but I have no idea how it worked.
I’ve wrote that comment many years ago, but will repeat that without rate reducer, Vz61 would be completely uncontrollable and thus in same dubious usefullness category as Ingram (and similar) models.
I’ve always wondered why Gordon Ingram seemingly didn’t try to cut down the rate of fire of the M10, M11 etc. As the video points out it has a small buffer, but there’s nothing else to stop the bolt from slamming back against the receiver. The main criticisms levelled at his SMGs were the ergonomics and the ludicrous rate of fire, which made it very hard to hit anything accurately beyond point-blank range. If he’d put some weights into the bolt, or added some kind of roller system to the slide, the M10 might have been better received.
But on the other hand perhaps Ingram expected it to be used at contact distance, as a last resort, in a “the attacker absolutely has to die” sense. The Beretta 93R seems to have the same design philosophy – instant firepower for bodyguards who might have to kill an attacker at point-blank range before he can detonate a bomb vest or pull a trigger. Who knows.
It’s also fascinating how the M3 Grease Gun has such a low rate of fire despite apparently having no special mechanism for it. Chunk-chunk-chunk, judging by Ian’s video from a few years ago. As far as I can tell the only reason is the heavy bolt, but it looked incredibly controllable in comparison.
Ian explained why SMGs like the M3 have such low rates of fire, but he didn’t talk much about it because he regarded it as obvious. The Grease Gun has lots of free recoil travel in that long receiver. All of the MACs – in the interest of compactness – have both too-light bolts and insufficient free recoil travel relative to the cartridges they use. Adding heavier bolts works but not only makes the gun larger and heavier, it also greatly exacerbates the open bolt’s jarring impact in semiauto (where sensible shooters will make most of their shots).
The principle works both ways, and putting a .380 barrel into an M-11/9 leaves that still-compact SMG chugging along sedately with the right bolt mass for its cartridge and ample free recoil travel. Making the receiver a little longer would have a similar effect in 9mm, with a minor cost in compactness.
Several SMGs famous for their “clever” rate reducers would see similar or better results by simply moving bolt mass forward and using the receiver space for free recoil travel.
The M10 was already ludicrously heavy for its size. Adding even more weight to the bolt would not have improved it. There’s a good reason a lot of 70s/80s special units bought a few, tested – or briefly – used them, and then junked them.
“Why he didnt…”
Slowing the rate of fire in Ingram sized gun (and weight) is bigger undertaking than designing the whole gun. Sometimes you cannot force 10-20 pounds of stuff in 3 pound sized bag.
Imo, that whole smg was been designed and made more as a gimmick (to trick the buyers into buying something at glance, being “very cool” but quickly realizing its pos), then serious military weapon. I also think his designing career ended up in a “blind alley” when he spent most of his mature efforts solely on “Mac” and feuding with a company they fired him from, instead of moving on to design and produce something other, better.
Yes, I know he had some (failed in trials) rifle designs later in attempt to sold to Africa or middle east iirc, but it was too little, too late.
From what I could work out, the Ingram SMGs were more marketing tools for the silencer side of things than they were serious machineguns.
It was a system; without the proprietary silencer, there wasn’t much point to the SMG. Without a compact SMG, the silencer wasn’t as useful, being too damn big for a pistol, and too ungainly on anything else.
In the age-old question of which came first, chicken or egg, I’m pretty sure that the silencer came first, and the SMG was an afterthought meant to make it really worthwhile.
Understood on the marketing gimmick origin, but several people succeeded (and to a much greater extent than the silly gimmick on the Skorp). The Lage bolt makes the upper just 7-10mm taller (I don’t have it in front of me), and others have used tungsten (which works in the stock factory upper). Either way, it’s still shorter in both height and length, as well as lighter – not only than any traditional SMG, but even the “modern, innovative” MP-5.
Mil.arm.corp should have researched these options back in the day, imo.
However, I know that now its happening because shooters do not have other cheap platform of machinegun, legally, so they want to get the most out of legal receiver. I’ve even seen, online, Ingram turned into “Pulse rifle” of Aliens!
Storm,
You are exactly right, and I’ll have to research that “Pulse Rifle” – thanks!
Its called Max-41A
https://www.max-11.com/TopSecret.html
Thanks, Storm! Amazing that they went through the arduous ATF process, and then never put it into production.
Simplest explanation would be its probably even more niche product, as what Kirk says about mp44. Cool to see but would not fly on the market for more then a dozen buyers, and I dont know if there are regulations of having 2 guns combo, in one gun.
I don’t disagree at all. I was just referring to the fact that the approval process is onerous (it’s where the Rule of Law goes to die), and it was bizarre that they went to the trouble for such an obviously niche product in the first place.
“(…)others have used tungsten (which works in the stock factory upper)(…)”
Keep in mind that Ingram designed said weapon also to be possibly easy in production, adding somewhat exotic material, which was both greatly more expensive than steel and requiring additional tools to work with is counter-productive for that.
According to https://www.usgs.gov/centers/national-minerals-information-center/historical-statistics-mineral-and-material-commodities in 1965 cost of 1 ton* was 131 for steel and 3800 for tungsten.
*metric
The tungsten slowfire bolt is $780, about 3.5x the cost of a factory bolt, but slightly cheaper than the Lage bolt assembly (because the latter requires a new upper).
A MAC plus either choice is much less expensive than most other SMGs in our [admittedly highly distorted] market.
I have always thought that swapping out a simple weight in the bolt, as in the Czech ZK383, is the slickest way to change the RoF of a weapon.
My vote for the most interesting rate reducer is the one in the Spanish Unceta “Astra” Model F Mauser C96 copy. A flywheel tucked away inside the “broomhandle” pistol grip which by opposing the bolt’s return stroke via a ratchet arm, brought the rate of fire down from the usual 1,200 R/M cyclic rate seen on the Mauser 712 “Schnellfeuer” to a more controllable 350.
Apparently, it was how well the Model F, Royal, and other Spanish selective-fire copies of the “Broomhandle” sold in faraway places like China that caused DWM to to develop their own version to begin with.
cheers
eon
I didnt know of it, but this is a(nother) great example of added value which turns something from dubious into useful “product”.
Now modern, there was some UK made gun project 30y.ago that had it electronically regulated, I think mechanical is the best way to go
https://guns.fandom.com/wiki/Parker_Hale_PDW claims that
The PDW was a blowback-operated submachine gun that utilized a hydraulic regulator to moderate the rate of fire. This was electronically powered by batteries stored in the pistol grip. The regulator could be modified to give fire rates between 200 and 400 rounds per minute; disabling the regulator would cause the weapon to fire at 1,400 rounds per minute.
I can’t recall where I read about it, but wasn’t there a fully-automatic weapon that allowed you to control rate of fire pneumatically? Had a set of seals on the blowback bolt, and a valve affair at the butt-end of the receiver?
At the moment, I can’t remember the details, and the search terms I’m using turn up nothing.
Was it US6782791B2 https://patents.google.com/patent/US6782791 ?
Nice find, first time I see this.
Grip looks like some klingon war blade, lol !
That was supposed to be one of the features of the Benet-Mercie’ aka Hotchkiss MG family. Chinn Vol. 2 goes into some detail on the “airlock” system that eventually was discarded on the French and U.S. versions but was retained on almost every Japanese variant up to the type 99 LMG.
Yes, I know the Type 99 is supposedly a ZB26 clone, but that’s only cosmetically. As W.H.B. Smith pointed out, inside, it’s a Hotchkiss just like every IJA MG before it.
The Hotchkiss “air-lock” also shows up on the IJA’s Nambu Type 1 and Type 2 SMGs. Called an “air buffer”, it was intended to reduce the rate of fire with 8 x 22mm ammunition from 1,300 R/m to a more reasonable 500.
The buffers’ protrusion aft of the trigger and etc. has often caused people to label these two as “bullpup” designs. They’re not, they just have a pneumatic rate-reducer in an aggravating position.
In all cases, the pneumatic buffer setup was used to allow a lighter bolt and thus reduced overall weight while retaining a reasonably-controllable rate of fire.
AFAIK, the only MG that ever had a wholly functional RoF control unit was the original Maxim of 1886, which had a purely mechanical one. The idea being that when on a tripod or wheeled mount, with what amounted to a “battle box” loaded up with a few thousand rounds of fabric-belted ammunition, it could be set in position, a pair of range stakes pounded in either side of its business end to limit traverse, the fire control set for your choice of one round a minute, or a 10, 20, or even 100 round burst, say every ten minutes, the traverse lock released on the mount, and from then on it could be left to its own devices to interdict an area as long as it had ammunition.
Or at least scare the mortal s#!t out of everybody on the other side of No Man’s Land for a few hours.
In the end, even Hiram Maxim gave up on the idea, possibly at the instigation of Vickers Ltd. This “feature” was not found on the first Vickers-built Maxim, in .577/450 Martini-Henry, or on any subsequent version.
cheers
eon
“(…)AFAIK, the only MG that ever had a wholly functional RoF control unit was the original Maxim of 1886, which had a purely mechanical one.(…)”
Never underestimate French technical though http://modernfirearms.net/en/machineguns/france-machineguns/puteaux-m1905-eng/
The muzzle cup is equipped with a mechanism that permits adjustment of the bullet / powder gases exit hole at the front. This, along with the adjustable buffer in the action, enables an adjustable rate of fire,with cyclic rates of between 30 and 600 rounds per minute.
After Ian displayed the Chauchat as one end of the spectrum, I was a little disappointed that he did not produce THE “real stuff” example that could fire at “insane” (his words) 1500 rpm: the MG42.
1500 rpm is not a propaganda figure. The British as well as the Soviets measured it.
Its predecssor MG34 fired at 900 rpm. It was Norwegian Folke Myrvang, who in his book about MG34 and MG42 for the first time showed the rate reducing mechanism that the MG34 originally had in its grip assembly. (The first 2300, I think.) It was invented by Louis Stange of Rheinmetall and covered by German patent 686843. The intention was, as elsewhere, using low rate of fire against ground targets and high rate against airplanes. In the end it was dropped and the high 900 rpm became standard.
German preference for high rpm (postwar MG42 version), while the rest of the world prefers slow rpm, has never been seriously discussed in military literature, as far as I know. Often the level is not much above “The Germans lost WW2, so their machine guns tactics must be junk.” Apart from a few people, like Kirk, it is typically overlooked that infantry combat was mostly decided by calling in U.S. artillery and close air support. There must be a reason, why the U.S. Army produced a propaganda movie (F.B. 181) trying to debunk German fast firing machine guns. Did the troops in the field not share the official mantra of Germans prematurely running out of ammunition because eof high rpm and not hitting anything in the first place because of large dispersion? In any case, the examples shown in the movie are unconvincing to the critical observer.
Not to be misunderstood, current German military decision makers do not have the slightest idea why high rpm was preferred by German infantry. Russians and Americans prefer slow firing machine guns, so that must be the way to go in their view.
What is totally lacking in my view is a sine ira et studio study of high versus low rpm, taking into account the reports of those at the receiving end.
From what I have read, allied troops feared the rate of fire of “Spandaus”, as they called MG34s and 42s, especially when they compared it to the chug-a-chug fire of their own machine guns.
JPeelen said:
“German preference for high rpm (postwar MG42 version), while the rest of the world prefers slow rpm, has never been seriously discussed in military literature, as far as I know.”
The reason it’s not discussed in the literature all that much is because the majority of the actual German literature is still buried in the archives and so forth. It was never discussed in either US or UK literature because the numpties doing MG doctrine didn’t understand it and dismissed it all.
The Germans had their reasons, ones they’d arrived at after long experimentation. If you look at the various German MG prototypes and transitional systems between WWI and WWII, it was a steady trend of increased rate of fire.
The reasons for this stem from the German observation that the higher the rate of fire, the better the casualty rate generated at long ranges. Since they wanted to keep the enemy as far away from their troops as possible, they did everything they could to maximize the number of rounds falling in the beaten zone at those ranges. If you are under fire from a slow rate of fire MG, you can get react quickly enough to get down below the grazing fire before the full burst hits. At the typical 1200rpm of the MG42, that burst is going to hit the entire beaten zone quickly enough that nobody inside it will be able to react.
The German desire for high RPM MG systems was predicated on killing the most people possible, as far away as possible. They also acknowledged that if you saw one guy at that range, more than likely he was part of a unit, and it was worth shooting up the entire area around him just on speculation. You can’t do that effectively with a low rate of fire weapon, soooooo…
The successor to the MG42 was supposed to have an even higher rate of fire than its predecessor, something on the order of 1500rpm. This was a requirement; they knew what they wanted, why they wanted it, and felt it was important enough to set their procurement criteria on it.
The typical 600rpm of your modern MG system is a marker that the people specifying that don’t understand why the Germans did what they did, nor do they understand how the Germans used their guns. For the Germans, the MG system was the pre-eminent direct fire system for the infantry; they did everything they could to maximize its lethality. In their tactical and operational system, the key maneuver element was not the individual rifleman, but the MG team. The riflemen were just there to carry ammo, scout, and provide local security for the gun. This mentality was why the Germans always prevailed on Allied infantry when the fight was limited to just the organic weapons of the infantry.
The key insight here is to recognize the idea that the machinegun is basically an automated replacement for the old-school and highly outmoded infantry volley tactics. One machinegun was effectively worth what a company or battalion of rifle-musket armed infantry were worth in the previous century, and that MG was much more mobile and maneuverable than an entire battalion of conscripts standing in ranks. The basic tactical idea was to maneuver firepower, vice manpower. Allied infantry used their MG systems as supporting weapons; Germans used their MG systems as the main effort, and their riflemen as supporting elements. Which worked better? Look at the exchange rates on the Eastern Front for a clue…
Absent the extraordinary provision of supporting arms to Allied infantry, I suspect that those rates would look even worse, and we can see in what happened in Afghanistan exactly why our purblind ignorance and inability to clearly understand what happened in WWII is still crippling our infantry operations, especially when the idjit class decides to write ROE denying use of all those supporting fires.
Modern NATO MG systems are purely intended as supporting weapons for Allied infantry doctrine, which I feel is inferior when you restrict it to a purely organic infantry weapon fight through something like ROE or logistical constraints. I’ve played with both in peacetime training, and I’m here to tell you that even with a low rate of fire MG, you can do a lot more damage simply by recasting your tactics to reflect the MG system’s primacy. Get your guns in behind the enemy, take them under fire, force them to withdraw… Hey! Presto!! No more casualty-producing frontal assault on their prepared defenses.
It’s a much more elegant solution, one that reduces your own casualties considerably. If you want to go ahead and do a “Hey diddle-diddle, straight down the middle…” attack, feel free.
Just remember, afterwards? You’ll be writing fewer letters home to the wives and kids of your casualties if you decide not to follow that particular line of stupidity.